Spark-plug.



H. F. SADGEBURY.

SPARK PUIG.

APPLICATION FLEU NOV. IU\ 1913.

1,269,86. Patented .1mm 18, 1918.

H. F. SADGEBURY.

SPARK PLUG.

APPLICATION min N0v.104 1913.

Izltfnted J une 18, 1915i 2 SHEETSSHEET 2.

fwmam SuM-rg, 5y y @4km/lm ATTORNEY W WW UNITED STATES PATET FFICE.

HERMAN F. SADGEBURY. 0F DAYTON. QHIO, ASSIGNOR. BY ME WOLVERINE SPARKPLUG COMPANY, INC

PORATED IN 1916.)

SPAR K-PLUG.

Continuation of application Serial No. 660,059, tiled November 13, 191i.

Serial No. 800,361.

7h uit] `whom it may concern Be it known that I, HERMAN F. SADGE- BURY,n eiti/len of the lhiitetl Stuten, resitlingr` nty 12S lurli street, inDayton, county of lltlontgoniery, und Stute of Ohio, linie inventedeert-nin new nntl useful Improve ments in Spark-llugsq ot' hielt Yltleelttre the following to he :t full: elettr, untl exact description.

This invention reltttes to spark plugs for internal combustion engines:intl more p:tr tieularly to n wu); of securing the insulator in thecylinder whether hy seeuriunr it in tt bushing tletttehnhlyY niountetlin the ejelintler us is customary or hy omitting; the tlettn-hnl lebushing :intl infetti-ing the insnlntor ilirectzljyr in un opening inthe engine eylintler. It is iletl as u continuation or substitute for mypendingr application No. titjtittlll filetl November 13, i911 disclosingttll thut is disclosed in smid pentling application hut containingndtlitionnl mutter hesitles.

)ne of the innin olljeets of this invention wus to provide suchconnection between the insulator :intl the meinher in which it is tosent and such Ineens for holtlintgT the former in the lutter its topermitI ot' verY rupitl removal of it therefrom unil without the ne-Cessity of using :t Wrench or :my tool in sut-h operations. Along withthe provision of quick attnchnhilitjtY :intl tletuehuhilittY ol' theinsulator it wus of course also retnetnlleretl that the Ineens tor ixingunt! holding the insulator in plut-,e would hure to be, hie-hl)`effective to hold the lutter etl'eetively in ploetiu its Sent so ns toprerent lenletge ol' ,ons from the cylinder when nncler eotnpression:intl it was :1n object of my invention to pro vit'le meansaccomplishing this.

The above objects :1re :tcoontplishetl with my invention by the use of nrotntuhle niember haring :t handle shnpetl tor convenient grasping' lo)Vthe hnnfl. so that, it muy l e munuallv turned und hnvine :t lienriug orllenr ings in some tiXctl tnenilter suer ns the hushing` in which theinsulator is to sent. or if there is to lle no bushing. in n tient-ing;or beurings rig-itl with the engine easing. :Intl having t1 caniportion, or :1 portion eeeentritj; to the axis of the bearings whichacts either directly, or through some intermediate con neetion, upon theinsulator, when the rotte table member is merelyv rotuterl. und withoutbeing given tiny other movement Whitt-ever,

Specification of Letters Patent.

ASSIGNMENTS, TO A CORPORATION "JF NEW YRK, (INCOR- Patented June i8,1918.

his aplllieatien. filed` metemeer 10,

in suoli n nity :as to 'loree the insulator tirnlly to its sent; nullhohl it there until the rot tltehle in cnln or eccentrie portion ol tinIrotittnhle pressing on Velten the insnlntor is thus 'r'eetl 'theitetttlntor.

table member is tttlnptetl to lle withllruwn from its bearings, it neeclhe, to permit eentplete. wttthelrnwnl of the tnszulntnr from its sont.4

his withdrnn'nl ol the inenlutor is nsenl :intl tlesirultle Y[or ent-himposes :ls cleaning the instllntor.` illumine or :nljustlnl: theelectrode or electrodes enrrtetl therelly,

for priming the engine` or eren another insultttor or elementJ for thesuhst it ut ing: substituting another insulntor for use for some otherPurpose such :is :in :tttnclnnent tor eonnecting' u pump with the engineso that the letter muy operate the formel:

The ahove principle ol' operation is npplied in n nlnnlter of dill'erentformsy of eon struction herein shown :mtl tleserilietl nntlunquestionubly other loi-ins een reutlily he devised making use. ofYin); novel priueiple ot operation.

The ntunher herein tliselosetl,

however, ure lielieretl sullieient to eompletel)Y indicate my inventionunil tell hon' it muy lie ronde use of.

lense the pressnre on the insnlutor.

more the insulator entirel \Y frena its sent the rotntuhle Int-inhetispulletl nxiullv out of its hearings nml the opening: in the insulator'whereupon the insillutor is completely treed for n'mnnnl reinornl frontits sent ln another l'orm illustrntetl l ntnlie use ot two pins orrt'ltntnltle tueinllersv hztting earn or eeeentrie portions projeetinnover shoulders on the insulutor insteznl ot hzttng :l singlerotultztllle ntetnlfetextending! through the msniutor.

ln still :mother torni l use n single rotti-- tablen'ielnller but here|t extentl through n noteh in the sitle of thr ins'ttlntt tnstentl ofthrough n hole through the insulfetor,

I have :stili further illtwtrnteti; n form in rotalalrile member doesnot extend n olf the insulator at all. but has bearings on the bushingand extends tenen alli.A longitudinally of the plug and at the side ofthe linut-alor and with the` direction of action oi the com or`eccentric portion of the rotatable member transverse lo the axis of theinsulator. Yln this forni .l niake use of a wedge extending through atransverse opening in the insulator having end bearings in the bushingand abutting.: at one end against the rotatable member and adapted. whenthe rotatable member is rotated in its bearings. to be movedtransversely of the plug and in such movement by reason of its` Wedgeaction on the insulaire. forcing the latter, at an angle to thedirection of 1no\e ment of the Wedge firmly against. its seat in thebushing.

It will be seen that in all there forms it is immaterial sofar as mybroad invention is concerned, whether the cani or eccentric portion ofthe rotatable member acts directly upon the insulator or through someintermediate element or elrnnents; also that it is immaterial whetherthe ellective action of the cam or eccentric portion of the rotav tablemember is in the direction of seating 'movement of the 'insulator orsome other direction with suitable connections, such as the Wedge shown,for changing the direction of action of the force applied to canse it toact to move the insulator tirnxl y against its seat.

In the preferred form in which the rotatabie member extends transverselythrongh the insulator I may so shape the hole in the insulator that therotatable member cannot turn all the way over but only slightly past thepositirjni at which it has imparted the grratest movement ordisplacement to the insulator, whereupon its cani or eccentric portierengagea the side of the opening in the insulator and prevents itsfurther rotation in that direction.` and since the rotatable member isthen slightly past its position iniparling the greatest throvv' to theinsulator the latter will have to be again tightened' slam-what againstits seat before the rota taliltmember can be turned back to its startihpj position. lli'ith this construction when lll;- :faior is fully inplace it more or less loi .rd there by the eccentric or cani portivo. ofthe rotatable member which elferivvlf( :x1-is f; arf; jarring or lighttaps tend-- ing .to lm n the rotatable member and ilwnngh it free theinsulator. Of course this limiting of the rotative movement of therelai-.dilaineinbt-r may be arizon'iplisln-.d in other 'vnf-'s .so as loaccomplish the lockingy action w. the insnlatrn'v For example, thehigiene? 'n efr-*inv casing! may be provided we desired testent, andthus lmnl', instead of the insulator, the rotation of the rotatablemember.

The above locking action of the rotatable member is not necessary,however, and, in fart, l pre fer to so locate the transverse hole in theinsulator that such will not result, as the friction between the cam oreccentric portion of the rotatable member and the insulator issufficient to resist all occurring accidental are or taps which mighttend to loosen the parts. But if it is desired to provide for limitingthe rotation of the rota table member l may make use of some fixed stopor projection on the bushing or casing to limit this rotation. n

More specifically it was an object of this invention to have theinsulator carry both electrodes and my invention embodies a novelarrangement of these electrodes and provides for electrical connectionfrom one of them to the engine cylinder by means of the rotatable memberwhen the latter is holding the insulator in its seat. Removal of therotatable member therefrom breaks the electrical connections andprevents sparking at the electrodes when the rotatable member is not inplace. By this construction one can quickly, by merely removing therotatable members of his spark plugs, render his engine inoperative byothers not having rotatable members fitting his spark plugs. It is notto be considered necessary to my broad invention for fixing theinsulator in place, that the insulator carry both electrodes for it may,if desired, carry but one, the engine casing or spark plug bushingcarrying the other in some Well known manner, and in this case therotatable member would not serve as part of the electrical connectionsat all. To the end that both electrodes can be removed with theinsulator for cleaning or adjustment and that their relationship willnot be changed in removing the insulator, l prefer to mount bothelectrodes in the insulator so that they are both carried by the sameelement. Some of the forms have shown both electrodes as carried by theinsalator and some but one and I may or may not, as desired, have therotatable member when in place directly engage with one end of oneelectrode. In one forni shown a little gap in which an additional sparkwill jump if desired is provided.

Since in the preferred form the bearings for the rotatable member arenot of the same diameter and the rotatable member must be placed in themin the saine relationship` and since in practice it is found that thebushings when screwed in the engine casinpr will not always present asingle sel. of bearings in the position most convenient for insertionand removal of the rotatable member. l may if desired provide aplurality of bearings or sets pf bearings for the rota` the removablerotatable member is in direct contact with one of the electrodes whenthe insulator is locked in place in the bushing. In this form also theopening in the insulator is so located, that one of its sides preventcomplete rotation of the rotatable member but stops it after justpassing the. posi tion effecting maximum displacement of the insulator.

i In the preferred form shown in Figs. 1 and 2, the plug is composed oftwo main parts, the bushing l and the. insulator 2, the former having anexternally threaded portion 3, by means of which it can be removablsecuredin a threaded opening in the wa l of an engine cylinder. Theinsulator 2 is adapted to be removably secured Within the bushin 1. Theinsulator in this form carries bot electrodes, 4 and 5, for the sparkthough it may carry but the one 4, if desired, leaving the other to becarried by the bushing. By the removal of the insulator from the bushingthe electrode or electrodes carried thereby are also taken out of theengine for examination, cleaning, or adjustment, without the necessityof unseren`Y` ing the bushing from the engine. The mem ber 1 ispreferably of non-circular shape at its upper portion whereby it can beconveniently operated by a wrench for inscri ion in and removal from thecylinder. The bush-- in 1 is hollow and the diameter of the axialopening is larger at the upper end than at. the lower externallythreaded end7 there being formed at the place where the diameter of theaxial opening changes an internal shoulder 6.

The exterior of the insulator Q is shaped at its intermediate and lowerportion to lit in the opening in the bushing l. It is provided with ashoulder T adapted when vthe insulator is in place in the bushin g torest on the shoulder 6 being, in use liowever, preferably separatedtherefrom by a gasket 8 of asbestos, copper asbestos, soft copper orother suitable material adapted to assist in forming between theshoulders a fairly gas tight connection to rerent escape of gas undercompression in t e cylinder. Instead of this type of gas tightconnection between the insulator and bushing I may omit the |gasketentirely and grind very smoothly the contacting surfaces ot' theshoulders 6 and 7 which does very well in practice in forming a gastight fit or I may employ, instead of the shouldered connections betweenthe bushing and insulator, a conical lit between these membersthroughout their length or .such of their length as desired. eithergrinding the contactingr conical internal and external surfaces andomitting a gasket of other material between them or omitting suchsmoothing operation on the surfaces and fitting a suitable gasketbetween the conical surfaces,

As indicated above the insulator is firmly forced against its seat andheld there, rev gardless of the particular form of seating connectionbetween the insulator and bush ing. by means of a rotatable memberjournaled in lixcd bearings und having a portion actingr as a cam.eccentric or crank when the rotatable member is turned to engage 'theinsulator and torce it lirmly against its seat in the bushing. ln thctorni illustrated in Figs. 1 and Q and now being described the portionol the insulator above the shoulder is provided with :i diametricalopening 9 counter bored at both ends at llfl and having the intermediatestraight portion l1 which is engaged by the rotatable member when thelatter rotated. to force the insulator against its scat in the bushing.The

bushing is provided near its top with diametrically opposite holes 1Qand 13. one or both of which are elongated somewhat in the plane of theopenings at right angles to the axis of the plug, and the verticaldimension ot the openings at right angles to the elonggation of theopenings are different for the different holes. The rotatable member 11ihas two concentric bearing portions 15 and 16 of different diameters andcorresponding respectively with the vertical dimensions et" the holes 12and 13 in the bushing. Between the bearing portion 15 and 16 is the cam,eccentric or crank portion i7 which, so far as its function isconcerned. may be either in general concentric with the bearings 15 and16 but having a cam portion on one side, maybe shaped olii' the centerof the bearings 15 and 16 on the order of a crank, or may be inst turnedaround but eccent rically to the bearings 15 and 16. Still other formsof the construction might suggest themselves but the one shown isbelieved sniciently illustrative. In it the intermediate portion of therotatable member bctween the concentric bearing surfaces 15 and 16 iscircular but turned eccentrically to the axis of the concentric 'bearingportions 15 and 16.

All that is necessary is that this portion of the rotatable member is ofsuch shape or contour that when the member is rotated some portion of itwhose periphery does not form a circle concentric with the axis of thebearings 'i5 and 16 will swing around and by engaging the insulator, andin the preY ferreel forni the bottom of the middle por tion l] of thediamci'rical opening! in it, torce the insulalor longitudinally of thebushing to firmly seat it against its seat in the buslr ing. linnn theparte. are in place the rotalalllv member extends through the transverseopening in lhe insulator and has its bearings 15 and lil restingresiiectively in the holes 1Q and l?? in the bushing. In this positionthc com. eccentric, or crank portion 17 of the rotatable member l-'i isWithin the opening 9 of the insulatorand when the parts are tight therotatable, member is in such angular relationship thaty the part ofportion 17 projet-,tingr farthest, t'roin the axis of the bearing 1:3and lt is against the lower surface 1l otl the openingr J and is holdingthe insulator lir1nl against its seat, Rota tion of the rotatable membercauses the eo Centric or ram portion 1T ot` it to move upwardly andrelease its pressure on the insulator. 'heu the parts are thus loosenedthe rotatable member Inav be axiallyr withdrawn from the holes l2 and 13and the opening: 9 of the insulator after whieh the latter can beuori'nallyv withdrawn troni the bushing. The. rotation ol tht-'member bythe opera tion ot' the handle brings the ram, errentrio or eranltportion in rontaet with the insuA lator or electrode means a-t a pointthat is in sulistantiel alinenient over the bearingr axis ofthe member`as well as with the point, ol 'ontaet ot' the member against thiIbushing;

.so `that these points item2' `itllattll Pause a substantially "deadrenter` eli'er't of the partsl involved. 'the result is. there is littleor no tendeney to rause the member to be turned backward or forward b vthe reaeting forces created when the member is rotated and the rainportion is brought into eontaet with the insulator. .\t least. nouionient of torre ot' sutlieient eii'ei-t to exi-eed the trietionalresistanee created b v the reaeting forces. This is mainly due to thetart that; the movement tending to rotate the cam either wa),y by thereacting torres is exerted Sol eilose to the axis of the rotatablemember as to be actingr practically on the line of the axis, andtherefore produeesl a moment ol forte insutlieient to overcome thet'rietiooal resistanee of the member against rotatirui` Should theinsulator he stuck somewhat in its` seat. turning of the rotatablemember hrough substantiall)Y 18() will. similarly, htough action of theportion 17 upon the upper surface of the portion 11 ot the opening 9,positively force the insulator up Wardly to loosen it. After thisloosening operation the rotatable member is axially withdrawn and theinsulator can be freely removed. The rotatable member in the forniillustrated in Figs. 1 and Q is provided with a bent portion 18 forminga handle through whieh it can be conveniently manually rotated, insertedand withdrawn.

The insulator of my plugr may be of an)1 suitable substance sueh aspoimelain or mica but I prefer to use a form of lava or other stone. Itis provided with a Contact screw 19 at its upper end adapted to beeleetrieally connected with one pole of a battery. the serew thereextends longitudinally through the insulator a conducting wire whichprojects centrally out through a conical recess in the lower end of theinsulator` the wire not going straight through from one end of theinsulator to the other but being bent around the opening 9 so as toleave sullieient insulation between itA and the openingr t) as well asbetween it and the exterior of the insulator. lVhile, as stated above,it is not necessary to have the insulator carry both electrodes I preferto have it do so and, in the torni beingr deseribed and illustrated inFigs. l and L. another electrode 5 extends longitudinally ol' theinsulator from about the renter ot the opening 9 to the lower end of theinsulator from which it. projects near the periphery. 'lhe projectingportion of this elet-trede is bent laterally at 22 beneath the end ofthe electrode -i and between these portions of the two electrodes inproximity to each other the spark is adapted to pass. The upper end ot'the electrode 5 makes eleelrieal eonnertion with the portion 1i' of therotatable member` which is made of metal, when the latter is holdingrthe insulator in plare .ind through this rotatable member the eleetrodeelefftrittalhv eonnerfts with the enveine ei linder from whieh therirt'uit is eontinned inthe usual wav back to theother pole oi' thebattery. jects. the rotatable member may or may not, as desired,directly Contact with the elect rode 5 toi it may. he just close enoughto the eleetrode so that a` spark will also leap aeross the gap betweenthese elements. if such is desired7 as is sometimes the ease. In eitherease axial removal of the rotatable member serres to etlif'tivel)v breakthe elet'trieal oirenit for the sifiarl; whieh will not occur until therotatable member is again properl)7 inserted in place.

As shown in Vig. i: the bearings 12 and 13 for the rotatablemember itare elongated to permit a little angular or bodily displafiment of therotatable member to take eartot' variations in location in a transverseplane of the opening 9 of the insulator whieh inav oeeur in practice.Either or both ot them may be so elongated or, by aeeurately locatingthe hole in the insulator and those in the bushing, this elongation ofthe holes 1Q and 13 may be omitted entirely though l prefer in practiceto elongate at least one of these a little.

ln the forni of the invention shown in Fig. 5 the shape of the openingin the insulator is changed as is also the horizontal holes in thebushing as instead of the rotatable member passing throuafh them a Wedge23 iasses through these holes and opening, which wedge has an inclinedportion 24 engaging the similarly inclined portion Q5 of theintermediate lower portion Y26 of the transverse opening 27 of theinsulator. The ends of the wedge have straight, bearing portions 28 and29 of ditt'erentl size adapted to work in eorrespondinglv shaped holesin the bushing. The wedge ot' this forni is adapted to be movedtransversely through the As indicated above in the obinsulator by meansof the same kind of a rotatable member 14 as in the referred embodimentbut mounted vertically in bearings 30 projecting from the side of thebushing. The dilference in construction of this form over a preferredform described above is that the rotatable member instead of extendingtransversely through the insulator and acting directly upon it to forceit against its seat, has its effective action transverse to the axis ofthe plug, and acts through the Wedge to force the insulator at rightangles a ainst its seat in the bushing. To remove t e insulator of thisform from the bushing the rotatable member must first. be loosened andmoved vertically cndwise from its bearings and then the wedge extendingthrough the opening in the insulator is with drawn whereupon the latteris free to be removed. The reverse of this operation takes place inassembling the parts.

Fig. 6 may be described as showing a modification in which thebushinglis omitted entirely as a part of the plug. n this the insulatorseats directly in an opening in the engine cylinder in the same way theinsulator of Figs. 1 and 2 seats in the bushing 1 Ears 31 projectingfrom the cylinder have bearin hooks against the lower sur faces of whichthe rotatable member seats at its bearing surfaces 15 and 16 as itsportion 17 is forcing the insulator in place or holding it there. 'I heaction of the parts is otherwise the same as in the form of Figs. 1 and2.

In Fig. 7 another modification is shown in which the insulator 2 is cutaway at dia mctrically opposite portions at 34 to form shoulders 35.and, instead of a single rota table member being used, passing throughthe insulator as in Figs. 1 and 2 two short rotatable members 36 areemployed each Working in its single individual bearing in the bushingand having a portion 37 adapted to engage its shoulder 35 of theinsulator and the two together act-ing to 'force the latter against itsseat in the bushing. In this forni but one electrode is shown as carriedby the insulator though obviously this form is also susceptible o havingthe insulator carry both electrodes as by running one end of one to oneof the shoulders 35 for engagement with its rotatable member 36 when thelatter is tightened down in place. In this form, to remove theinsulator, both rotatable members are rotated to loosen them and thenare axially withdrawn. whereupon the insulator may be axially removed.

In connection with this form carrying but one electrode I have shown anadjustable element 38 screw threaded at 39 'o detachably cooperate withinternal screw threads 40 on the lower end of the bushing. In this waythe distance of this clement 38 from the electrode 41. carried by theinsulator can be varied. The upper sido ci. the element 38 ifi chamberedat 42 and between the element and the lower end oi the electrode acombustion chamber including` the chamber 42, is formed. Downwardlyextending and diver-ging openings 43 start adjacent the electrode 4l andextend through the element 38, and these openings serve to spread theignited and iaming gases in the combustion chamber as they rush outthrough them after being ignited. The ignition in the-combustion chamberis caused by sparks passing from the electrode 41, to the adjacentpoints` on the upper surface of the element 38 which is of metal andbeing electrically connected with the bushin serves as the otherelectrode with a plurality of contact points around the end of electrode41. B means of the rushing oi' ignited gases in al directions from thewmlulstion chamber through 'ine small openings 43 in the element 38 theignited and burning gases are distributed more or less through thecylinder and a more complete ignition and combustion of all the fuel inthe cylinder results. The spark gap can be varied by merely adjustingthe element 38 vertically in the lower end of the bushing. Of coursethis feature of the invention can be used even though the insulatorcarries both electrodes, and can be applied to my preferred form bymerely extending the lower end of the bushing Shown in Figs. l and 2,and internally screw threading this lower end a l screwing the element38 therein. In this form the ele- 100 ment 38 would not need to form anelectrode but `would serve to forni the combustion chamber and todefiect the iifnited gases they rush therefrom into the cylinder afterhaving been ignited by the spark pass- 105 ingbctween the electrodesshown in Figs. 1 and which in such case would occur withir thecombustion chamber.

ihc form shown in Fig. 8 is similar to that just described except that asingle ro- 3 i retable member is employed which instead of passingthrough a diametrical opening in the insulator passes through a notchcut in the side of the insulator2 and serving the same purpose as theopening 9 of Figs. 1 11.5 and 2.

Relative to the embodiment of my invention shown in Figs. 10 to l5 theoperation is more or less the same as in the other figures. A type ofscrew thread or the bushing is 12o shown which is dilerent from thatwhich is shown in connection with the other ligures, though this doesnot affect my invention at all as also does not the differentconstruction or' 'dul end of the rotatable member 125 which instead of abent handle of the other forms, consists of a knurlcd head 44. In theforni shown in Figs. 10 to 14 I propose to force and hold the insulatorin place not by direct engagement of the portion. 1T of 130 therotatable member with the bottom of the transverse opening 9 in theinsulator but through the medium of a ring 45 surrounding the insulatorand located between it and the bushing and restin upon and actingagainst the upwardly acing shoulder 46 on the periphery of theinsulator. The ring 45 has oppositely disposed openings 47 through whichthe rotatable member passes as well as passing through the transverseopening 9 in the insulator and the extremities of the portion 17 of therotatable mem ber are located in these o enings 47 when the parts are inplace and) serve when the rotatable member is rotated to force down thering 45, and by reason of its seating on the shoulder 46 of theinsulator, force the donwardly facing shoulder 48 of the insulatordownward against its seat or shouh der in the bushing or against agasket on the. seat in case a gasket used. In this form I have shown theopenings in the ring of such shape and location as to have acorresponding side of each opening nearer the axis of rotation of therotatable member than the other sides so that the portion 17 of thelatter member will be carried against such sides of the openings in thering after just passing the position at which it displaces the ring andinsulator downwardly the maximum distance, which sides of the openingsin the ring will thus serve to prevent further rotation in thatdirection of the rotatable member. Also when the rotatable member isthus stopped from further rotation it cannot return to release theinsulator without sufficient force being applied to rotate it back pastits position calling for maximum displacement of the insulator. By thisconstruction the rota table member when rotated until it is stopped bythe sides of the openings 47 in the ring acts more or less as a lockagainst unseating of thel insulator by any accidental jar or tap.

A similar action is presented in the form shown in Fig. 15 which in thisrespect dit fers only from the form of Figs. 10, 11, and 12 in that thering 45 of the last mentioned form is done away with and the openin inthe insulator shaped and located just ike the openings in the ring thuspresenting a construction in which the locking and seating operation ofthe insulator is the same except that the portion 17 of the rotatablemember coacts directly with the bottom and 4side of the opening in theinsulator and 'not through the intermediate ring. Of

course in this form, I do not need the upwardly facing shoulders on theinsulator Within the bushing and the insulator is shown as completelyfilling the bushing at this point. In the illustration in Fig. 15 I alsoshow the upper end of one electrode in direct contact with the rotatablemember instead of slightly separated therefrom as in Fig. 11 to form asparking gap at the juncture.

The above description I believe, sulliciently illustrates my inventionso that one skilled in the art can readily make and use it. I wish ilylo be distinctly understood however that the various forms are merelyillustrative. I now [mrceivc Various other forms in which it may beembodied but which it seems needless to describe herein. As concerns mynovel way of forcing the insulator of a spark plug to its seat andholding it there it is immaterial whether the iusulator carries bothelectrodes or not or whether, if carrying both, the second one makeselectrical connection with a engine for return to the battery ormagneto, through the rotatable number or not. l have shown and nowprctcr such construction it being a very convenient arrangement and onein which. the usefulness ot the plug may be temporarily and quicklydestroyed so that the en'gine cannot be run. by merely remoi ing therotatable member from its place. This provides means whereby the ownerof an engine can, by merely removing the ro tatable member, readilyprevent removing of his engine by someone not intended to run it andhaving no rotatable member of such size and shape as to tit his plug.This feature of the invention I howex'er also desire protection for andaccordingly present claims directed to it. I also consider it to beimmaterial so far as my novel Vay of fastening the insulator in place isbroadly concerned, whether the rotatable member acts directly on theinsulator or through an intermediate element such as the ring shown inFig. 11 or the wedge shown in Fig. i; whether the rotatable memberextends transversly of the plug as in most of the tigures orlongitudinally as is illustrated in Fig. 5; whether there is a singlerotatable member as in most of the figures or a plurality ot' them as inFig. 7; whether the rotatable member extends through the insulator orjust over it as in Fig. 7; or whether as in Fig. 5 another elementpasses through the insulator; or, if some element is to 'pass throughthe insu-A lator. whether it is through a notch in the side of thelat-ter or through a transverse opening in it; whether the rotatablemember is to be prevented from complete rotation when in place and isrotatable in but one direction to seat the insulator` to its seat as isthe case with the forms of Figs. 10 to 15, or Whether the rotatablemember can be rotated in either direction. to maximum displacement otthe insulator, and in either direction to release the insulator as inthe forms shown in Figs. l to i): or if complete rotation ot 'therotatable member is prevented whether this is done in the manners shownin Figs. l() to 15 or in sonic other some stop on the bushing forroi'ipcrating with some part of the rotatable member. In fact therotatable member need not be of the shape as shown but all that isnecessary is that it be so constructed so that at somo portion orportions along its axis of rotation its periphery is not a completecircle concentric with its axis of rotation so that such portion orportions will w hen the member is rotated cooperate either by directengagement or through some intermediate element or means, so as to movethe insulator to its seat and hold it there so long as the rotatablemember is not turned to relea se it. l have shown the member as havingbetween its concentric bearing portions a portion circular but turnedeccentric t0 the axis of the bearing portion or portions but plainly themember might be a substantially sii-aight member of circular crosssection but with a peripheral projection or cam at the lesireil point,or the same result would be awomplished h r a. member of circular crossIser-lion with `some point or portion bent out or' alinement with theportion to form its bearing. lt is also not even necessary to the use ofmy broad invention that a bushing be used as m some eases, aswithengines specially made. l desire to eliminate the usual bushing adaptedto detachably engage within an opening in the engine cylinder andjournal my rotatable memberdirectly in bearings on i Fig. t3, theinsulator seating in such case similarly to the Way it seats in thebushing in my other forms. It is only necessary that the rotatablemember be revented by some tixell member at its bearings from moving ina direi-tion reverse to that in which the eccentric portion of themember acts when forcingA the insulator to its seat. The throw of theeccentric portion of the rotatable member l may vary as desired and itis not even necessary that the rotatable ymember displace the insulatorthe maximum amount in order for the friction between the parts to holdthem in their moved position. 1t has been found in practice that therotatable member can be stopped in positions causing a varyingdisplacement of the insulator yet the friction without the lockingeffect described with reference toiFigs. 10 to 15 will be snlicient toretain the rotatable member and the insulator in their moved positionsuliiciently well for all practical purposes. 'lhis providest by varyingthe extent of rota'tion of the rotatable member, for varying the prcssuewith which the insulator is held in place as desired or by more or lessrotation of the rotatable member obtaining the .pressure desired inspite of slight' variations of the parts in manufacture. In fact bycaretally selecting the desired resiliency for the rotatable member apressure for the insulator on its seat is provided for which is subwaysuch as by the engine casing as shown inl effective.

stantially constant for all conditions and which cannot be exceeded nomatter how much force is applied to the rotatable member in rotating it.This feature l propose to use in manufacture and is of value inpreventing so much ressure being applied as to injure the ga et andaffect its durability or efliciency. In many forms of plugs this oftenoccurs when the insulators are fastened in place by means of a' wrenchand where it is easy to apply more than the necessary ower. My rotatablemember is designe or manipulation wholly by the fingers and without awrench and by varying the throw of the eccentric portion and itsperiphery or the distance from the axis of the rotatable member at whichthe fingers act, or both, it is easy to provide so that too much forcewill not be applied. The provision of counter boring the ends of thetransverse opening in the insulator is just as `useful in connectionwith any of the forms Where an opening extends through the insulator',though not `hewn in connection with Figs. l0 to 15. Such is also theprovision for clongatin the holes forming bearin. sin the bushin or therotatable member.

consider it quite an advanta e in my invention to be able, by merely suciently rotatin the rotatable member when turning it to re ease thepressure on the insulator, in the forms shown in Figs. 1 to 4, and 8 to15, to positivel carry the insulator away from its seat. T is I considerquite an advantage because in some forms of plugs it often occurs thatthe insulator becomes more or less stuck in its seat or bushing so as torequire some little eort to loosen it even when the member which holdsit in place is no longer lt is obvious that in my invention embodied inthe preferred form, merely rotating the rotatable member so as to carryits eccentric portion into cooperation with the upper side of thetransverse opening 9 in the insulator will serve to force the insulatorup instead of down and positively unseat the insulator should it bestuck in its seat. To apply this to the form shown in Fig. 6, in whichthe useful bushing is eliminated, the bearings for the rotatable memberwould, of course, have to be formed to coperate not only with the upperportion of the rotatable member as shown hat also would extend beneaththe bearing portions of such rotatable member.

With rnv improved way of forcing and holding a sparkplug insulator inplace the latter can be conveniently and readily removed without the useof a. wrench and equally as conveniently restored to its place in thecylinder. ln putting the insulator of my preferred form of Figs. 1 and 2in place it is first placed bv hand to its seat so as to aline itstransverse opening with the bearirgs for the rotatable member. Therotatable member is then inserted into its bearin s and through theopening' in the insulator. `urn- Jng of the handle. le of Figs. 1 and 2so as Vto stand upright then rotates the rotatable member to cause itsportion 17 to force the insulator firmly against its seat, and rictionof the parts is sutlieient to hold the parts in this position for al]practical puroses until it 1s desired to remove the insuliitors. 'hensuch is desired all that is neeessarv is to rotate the rotatable memberuntil it sufficiently frees the insulator' when it can be axiallyremoved. Then removed the insulator is free for longitudinal removalfrom its seat. It the insulator is stuck in place turningr of the handle18 vertically downward when the rotatable member is in place willpositively move the insulator upwardly from its seat and eliminate thesticking so that upon removal of the rotatable member the insulator maybe readily withdrawn.

The terms calm eocentrie, "*crankj lever where used in ther claimsindividually are to be interln'eted in generic sense to cover all theterms, where such interpretation is consistent with the novel operationof this device and the other phraseology of the claims.

Having described my invention and various embodiments of it what l claimas my invention isi# l. In a spark plug for internal combustion engines,the combination of lixed member having an opening,l a bearingr fixedrelative to said member; an insulator adapted to seat in said openingand carrying an electrode; and a rotatable member adapted to rotatewithin said bearing and having a eam portion adapted when the rotatablemember is rotated to force the insulator against its seat in theopening.

2. ln a spark plug?r for internal combustion engines, the eombimition ofaY fixed member having an opening; an insulator carrying un electrodeadapted to seatin said opening; bearings fixed relative to said fixedmember; and rotative means mounted to 1otate in said bearings and havinga cam portion adapted to force the insulator to its seat when therotatable means is rotated.

3. In a spark plug t'or internal combustion engines. the combination ofa fixed member having an opening; an insulator carrying an eleetrodeadapted to seatk in said opening; bearings xed relative to said fixedmember; and rotative means mounted in Said bearings and having a camportion adapted to torre the insulator to its seat when the rotatablemeans is rotated in one direction and to move the insulator from itsseat by movement in the other direction.

4. In a spark plug l'or internal combustion engines. the combination ofa bushing adapted to be removably secured in an engine Cylinder andhaving a bearing fixed relative thereto; an insulator adapted to beremovably secured in 'said bushing and carrying an electrode; and arotatable member adapted to be removably jonrnaled in said bearing andhaving a ram portion adapted to coat-t with the insulator when the rotatable member is rotated to move the insulator relative to the bushing.

:3. ln a spark plugnlr for internal Combustion engines, the combinationof a bushing adapted to be removably secured in an enL gine cylinder andhavintt a bearing fixed relative thereto; an insulator adapted to beremovably secured in said bushing and car-- rying an electrode; and arotatable member adapted to be removably journaled in said bearing andhaving?r a -am portion adapted to conet with the insulator when therotatable member is rotated to move the insulator in either directionrelatively to the bushing.

t3. ln a spark plugl t'or internal combustion engines` the combinationof a bushing adapted to be removably secured in an engine vlinder andhaving :i bearing tixed relative thereto; an insulator adapted to beremovably secured in said bushing and carrying an electrode; and arotatable member adapted io be removably journaled in said bearing andhaving a eam portion adapted to eoact with the insulator when therotatable member -rotated to move the insulator against its seat in thebushing.

i'. In a spari( plug i'or internal combustion engines, the combinationot' a bushing adapted to be removably secured in an engine cylinder andhaving a bearing fixed relative thereto; an insulator adapted to beremovably secured in said bushing, and earrying an electrode; and arotatable member adapted to be removablyy journaled in said bearing andhaving a cam portion adapted to eoact with the insulator when therotatable member is rotated to move the instr` lator to its seat in thebushinfY :ind hold it there until the rotatable member is turned torelease it.

8. In a spark plugr for internal combustion engines, this` combinationof a bushing having diametrieally opposite concentric bearing,ropenings; an insulator having a transverse opening therethrough carryingan electrode and adapted to seat in the bushing; and a rotatable memberhaving concentric bearing portions for location in thev bearing openingsin the bushingr and an intermediate portion for working in thetransverse opening in the insulator, the periphery of such intermediateportion extending tarther from the axis of the concentric bearintgrportions at some points than at others so as to. when the rotatablemember is rotated in its bearings, engage the inside of the opening inthe insulator andvmove the latter relatively Q0 lhe bushing.

9. In a spark plug for internal combustion engines, the combination ot'a bushing having diametrically opposite concentric beari g openings; aninsulator having a transverse opening therethrough carrying an electrodeand adapted to seat in the bush,- ing; and a rotatable member havingconcentric bearing portions for location in the bearin openings in thebushing and an intermetiate portion for working in the transverseopening in the insulator, the periphery of such intermediate portionextending farther from the axis of the concentric bearing portions atsome points than atrothers so as to, when the rotatable member isrotated in its bearings, engage the inside of the opening in theinsulator and move the latter relatively in either direction to thebushing.

10. 1n a spark plug for internal combusy tion engines, the combinationof a bushing having dianietrically opposite concentric bearing openings;an insulator having a transverse opening therethrough carrying anelectrode and adapted to seat in the bushing; and a rotatable memberhaving concentric bearing portions for location in the bearing openingsin the bushing and an intermediate portion for working in the transverseopening in the insulator, the periphery of such intermediate portionextending farther from the axis of the concentric bearing portions atsome points than at others so as to, when the rotatable member isrotated in its bearings, engage the insideY of the opening in theinsulator and move the latter relatively to the bushing against its seatin the latter.

ll. In a spark plug for internal combustion engines, the combination ofa bushing having diametrically opposite concentric bearing openings; aninsulator having a transverse opening therethrough carrying an electrodeand adapted to seat in the bushing; and a? rotatable member havingconcentric bearing portions` for location in the bearing openings in thebushing and an intermediate portion for working in the transverseopening in the insulator, the periphery of such intermediate portionextending t'arther from the axis of the concentric bearing portions atsome points than at others so as to, when the rotatable member isrotated in its bearings, engage the inside of thc opening in theinsulator and move the latter relatively to the bushing against its seatin the latter and hold it there until the rotatable member is turned torelease it.

v l2. In a Aspark plug for internal combustion engines the combinationof a hollow bushing having an internal shoulder; an insulator having anexternal shoulder adapted to rest on the internal shoulder;'a plurality.of diametrically opposite holes in the bushing; a transverse hole inthe insulator;

and a rotatable member mounted in the holes in the bushing and insulatorand having a cam portion within the opening in the insulator for forcingthe shoulder in the insulator irmly against the shoulder in the bushingwhen thc rotatable mcmbcr is rotated the cam portion ot' the rotatablemember serving when its cam portion is rotated beyond a position callingfor maximum displacement ot' the insulator to lock thc insulator lirmlylin place and to lock itself against turning to release thc insulator.

13. In a spark plug for internat combustion engines, thc combination ofa bushing adapted to be removably secured inan engine cylinder: aninsulator adapted to rest therein and carrying a plurality oi'electrodes; a contact screw electrically connected with one ot theelectrodes; a transverse hole in the insulator; diametrically oppositeholes in the bushing; and a rotatable member mounted in the transversehole in the insulator and the openings in the bushing adapted toremovably secure the insulator and 'bushings together.

1-1. ln a spark plug for internal combustion enfrines, the combinationof a bushing adapted to be removably secured in an'engine cylinder; aninsulator adapted to rest therein and carrying a plurality ofelectrodes; a contact screw electrically connected with one ot theelectrodes; a transverse hole in the insulator,- diamctrically oppositeholes in the bushing; ind a rotatable cam bearing member mounted in thetransverse hole in the insulator and the openings in the bushing adaptedto removably secure the insulator and bushings together.

15. In a spark plu for internal combustion engines, the com'iination ofa bushing; an insulator adapted to seat therein and carrying anelectrode; and a single rotatable member rotatable about an axis at anangle to the axis ot the plug for the purpose of locking the insulatorin the bushing.

1G. ln a spark plu for internal combustion engines, the com'ination of abushing; an insulator adapted to seat therein a transverse openingthrough the insulator; a member located in the opening and coat-,tingwith the bushing to hold the insulator in place; and an electrodeelectrically connected with the tx-'ansverse member in the insulator andtherethrough with the bushing.

17. In a spark plug for internal Combustion engines, the combination ofa bushing; a removable insulator therefor and carrying an electrode; arotatable member having a cam portion for forcing the insulator againstits seat in the bushing; and means for preventing further movement ofthe rotatable member after the cam has reached :its position effectingsufficient displacement of the insulator relative to its bushing.

18. In a spark plug for internal combustion engines, the combination ofa bushing; an insulator adapted to seat therein and carrying anelectrode; and a rotatable member having a cam portion for forcing theinsulator m place in the lushing when the rotatable member is rotatedthe insulator adapted t0 prevent further rotation of the cam after ithas reached its position displacing the insulator the most in the direction of its seat.

19. In a spark plug for internal combustion engines, the combination ofa member; a removable insulating element carrying an electrode; and arotatable member having a portion of its exterior eccentric to its axisot rotation such )ortion serving when the member is rotated to attachthe insulating element to the first mentioned member.

20. In a spark plug for internal combustion engines, the combination ofa bushing; a removable insulator adapted to be attached thereto carryingan electrode; and a member removably journaled for rotation in thebushing and having a cam portion serving when the melnber is rotated tomove the insulator transversely to the axis of the rotatable membenandattach it to the bushing.

21. An insulator for spark plugs haviner a transverse opening extendingtherethrough adapted to receive a securing` member for the insulator; anelectrode extending from the opening to one end of the insulator formingone spark terminal; and a/second electrode extending longitudinallythrough the insulator and forming another spark terminal.

22. AnA insulator for spark plugs having a transverse opening` extendingtherethrough adapted to receive a. securing member for the insulator,counter bored at its ends. an electrode extending from the opening toone end oi' the insulator foi'ining one spark terminal; and a secondelectrode extending longiturlinally through the insulator and vforminganother spark terminal.

In a spark plug for internal combustion engines. the combination of a.hollow bushing having diainctrically opposite bearing openings therein:an electrode carrying insulator adapted to seat in said hollow bushingand having a transverse opening therethrough counter bored at its ends;and a rotatable member passing through the insulator opening andjournaled in the bearing openings in the bushing and haring a pori ionintermediate its bearings where its periphery is at greater distancesfrom the axis ot' rotation ot the member at some places than at othersadapted when swung around upon rotation of the rotatable ineinbcr toengage tlubottom of the opening in the. insulator intermediate thecounter bored portions and `force the insulator bagainst its @eatin thebushing.

'24. Ina spark plug for internal combustion engines, the combination ofa bushing; an insulator having a transverse opening carrying anelectrode and adapted to scat in the bushing; a rotatable memberextending through the opening in the insulator and having cam portionfor forcingr the insulatoi in place in the bushing when the rotatablemember is rotated; and bearing openings in the bushing for the ends ot'the rotatable member one of these heilig elongated in a directionconcentric to the axis of fthe plug,

25. In a spark plug for internal combustion engines, the combination ofa hollow bushing; an insulator adapted to seat therein and carrying anelectrode; an electrode forminor element attached to the lower end ofthe bus ling and forming a chamber between it and the lower end of theinsulator within which is the electrode carried by the insulator; anddiverging openings in the electrode forming element for spreading theignited gases when rushing therethrough after being i nited by sparkspassing between the electrodges, the wallsl of said diverging openingsprovided with a plurality of points around the entrance to the openingsbetween which and the electrode on the insulator a series of sparksoccur.

2G. In a spark plug for internal combustion engines, the combination ofa hollow bushing; an insulator adapted to seat therein and carrying anelectrode; an electrode forming element adj ustably attached to thelower end of the bushing ind forming a chamber between it and the lowerend of the insulator within which is the electrode carried by theinsulator: and diverging openings in the electrode forming element forspreading the ignited gases when rush ing therethrough after beingignited by sparks passing between the electrodes, the walls of saiddiverging openings provided with a plurality `of points iround theentrance to the openings between which and the electrode on theinsulator a series of sparks occur.

2T. In an article of the class described..

the combination with an insulator carrying an electrode. of a bushingcontaining a seat for the insulator and having a pluralityl ofdiametrically disposed bearing openings` and cam bearing l meansrotatable in the bearing openings to engage the insulator and force itagainst its seat in the bushing.

28. A spark plug comprising a bushing having openings at right angles tothe axis of the bushing, an insulator carrying an electrode having anopening coperating with the holesin'the bushing, a rotatable member to.be inserted through the openings in the bushing and insulator and havingthe portions engaging the bushing concentric to one axis and the portionengaging the insulator concentric to a different axis.

29. A spark plug comprising an electrode carrying insulator, a bushinghaving an opening to receive the insulator' and bearings fixed withreference thereto, and a rotatable member adapted to cooperate with saidbearings and having a portion of its periphery projecting to engage theinsulator whereby when t-he member is rotated the insulator will bemoved axially in one direction or the other depending upon the direction in which the member is rotated.

30. In a spark plug, the combination of a bushing, electrode carryinginsulating means adapted to seat therein, and a single rotatable memberrotatable about an axis extending at a large angle to the longitudinallaxis of the bushing for the purpose of forcing the means firmly againstits seat in the bushing and automaticallyT holding it there.

31. A spark plug comprising an electrode carrying insulator, a bushingadapted to receive the same, and a member rotatably engaging in thebushing and i sulator to ro tate about an axis at an ang e to thelongitudinal axis of the insulator adapted to press in oppositedirections on the insulator and bushing when rotated, to force and holdthe insulator against the seat in the bushing,

32. A spark plug comprising in combination, a bushing, an electrodecarrying insulator removably mounted in the bushing, and a crank-likemember rotatably' engaging in the bushing and insulator and serving whenrotated to force the insulator' firmly against its seat in the bushingand to hold it ythere by reason of the crank-like member assuming asubstantially dead eenw ter relationship between the insulator andbushing.

33. In a spark plug, the combmation of a bushing member, an insulatormember adapted to seat therein, and a rotatable member rotatable aboutan axis at an angle to the axis of the other members and ful'-cruming'against one of the first mentioned members and acting againstthe other in lsubstantially alinng but oppositely directed lines of'action passing through points close to the fulcrum point whereby themoment of force tending to rotate the rotatable member through thereaction of the first said members will be too small to overcome therictional resistance against the rotatable member.

A 34. In a spark plug, the combination of a bushing, an electrodecarrying insulator adapted to seat in connection therewith, and 'arotatable member rotatably engaging the insulator and bushing about anaxis at an' angle to the longitudinal axis of the insulator, saidaxisbeing on a' line that will pass through the projected transverse area ofthe insulator, said' member serving to force the insulator to its seat.

35. In a spark plug, the combination of a fixed member having anopenime;` a bearing fixed relative to said member, an electrode carryinginsulator adapted to seat in the member, and a rotatable member adaptedto rotate against said bearing and having a portion adapted to actagainst the insulator when the member is rotated to press the in-'sulator against the seat in the fixed member, said rotatable member'having means whereby it may be operated.

36. In a spark plug, the combination of a fixed member having anopening, a bearing fixed relative to said member, an electrode carryinginsulator adapted to seat in' the member, and a rotatable ymemberadapted to rotate against said bearing and having a, portion adapted toact against the insulator when the member is rotated to press theinsulator against the seat in the fixed member, said rotatable memberbeing so arranged through the insulator and fixed member as to requirecomplete removal from both the same to permit them to be separated fromeach other.

37. In. a spark plug, the combination of a bushing 1nember,. a separablemember including an insulator, adapted to seat therein, and a rotatablemember rotatable about an axis at an angle to the axis of the othermembers and fulcruming against one of. the first mentioned members, andacting against the other in substantially alining but oppositelydirected lines of action passing through points close to the fulcrumpoint, whereby the moment of force tending to rotate the rotatablemember through the reaction of the first said members Will be too smallto overcome the frictional resistance against the rotatable member.

38. In a spark plug, the combination of a relatively fixed member; anelectrode earrying insulator adapted to seat therein; and a singlepressure applying element rotatable about an axis at a` large angle tothe axis of the insulator to lock the insulator to its seat.

39. An insulator for spark plugs having a portion adapted to be engagedby a securing member for the insulator, an electrode extending from saidportion to one end of the insulator forming' a spark terminal, and asecond electrode extending longitudinally through the insulator andforming another spark terminal.

40. In a spark plug, the combination of a relatively fixed member; anelectrode carrying insulator adapted to removably seat therein; and anelement. removable, by movement in a plane transverse to the axis of theinsulator, and adapted to be so actuated as to apply pressure to theinsulator i'n the direction of its axis to lock the insulator toitsseat.

41. In a spark plug, the combination of a relatively fixed member; anelectrode earrying insulator adapted to removably seat therein; and anelement, provided with an operating handle by which said element may beremoved by movement in a plane transverse to the axis of the insulatorand by which said element may be actuated so as to apply pressure to theinsulator in the direction of its axis to lock the insulator to itsseat.

'42. In a spark plu the combination of a relatively fixed mem er; anelectrode carrying insulator adapted to removably seat therein; and anelement, removable by movement in a plane transverse tothe axis of theinsulator and extending over a portion of the insulator, said elementbeing adapted to be so aetuated as to apply pressure to the insulator inthe direction of its axis 'to lock the insulator to its seat.

43. In a spark plug, for internal combus tion engines, the combinationof a ixed member having a seat and an Opening, an electrode carryinginsulator adapted to pass into the opening and against the seat and asingle manipulatively operable yielding pressure applying element forforcing the insulator against its seat in the fixed member and holdingit there in opposition to pressure exerted from the engine chamber whenthe plug is in use in the same.

44. A spark plug comprising a fixed member having an opening and a seatfor an insulator, an electrode carrying insulator adapted to pass intothe opening and against the seat and a fastening member disposedtransversely in the insulator and means whereby the fastening member maybe manually operated to exert yielding pressure on the insulator toforce the same firmly against its. seat in the fixed member.

45. In a spark plug, the combination of a bushing, an electrode carryinginsulator adapted to seat therein and rotatable, yielding, pressureapplying means adapted to rotate about an axis at an angle to thelongitudinal axis of the insulator in coperation with the insulator andbushing to force the insulator against its seat in the bush- 1ng.

46. In a spark plug, the combination of a bushing, an electrode carryinginsulator adapted to seat therein and a rotatable, somewhat yielding,fastening member forcing the insulator against the seat in the bushingwhen the fastening member is rotated when in cooperation with theinsulator and bushing.

47. In a spark plug, the combination of a bushing, an electrode carryinginsulator adapted to seat in connection therewith and a rotatableresilient member rotatably eo operating with the insulator and bush'mgabout an axis at an angle te the longitudinal axis of the insulator,said axis being on a line that will pass through the projectedtransverse area of the'insulator, said resilient member serving, whenrotated, to force the insulator against its seat.

48. In a spark plug, a bushing, an electrode carrying insulator adapted,to seat in the bushing and a crank like resilient member rotatablyengaging with the bushing and insulator and serving, when rotated, toforce the insulator against its seat -in the bushing and to hold itthere by reason of the crank like member assuming a substantially deadcenter relationship between the insulator and bushing.

49. In a spark plug, a bushing member, an insulator member carrying anelectrode and adapted to seat therein and a resilient member rotatableabout an axis at an angle to the axis of the other members and actingagainst the other in substantiall alined but eppositely directed linesof ae ion passing through points close to the fulerum point whereby themoment of force tending to rotate the rotatable member through the reaction of the irst said member vvvill be too small to overcome thefrietional resistance against the resilient rotatable member.

50. In a spark plug, a bushing, an eleotrode carrying insulator adaptedto seat therein and a cam like yielding fastening member adapted to berotated to apply a gradually increasing yielding pressure of 'theinsulator against its seat in the bushmg.

5l. In a spark plug, a bushing, an electrode carrying insulator adaptedto seat therein having yielding fastening means for holding theinsulator against its seat in the bushing, said yielding means directlyengaging the insulator and bushing and Inanually manipulative to applya. yielding pressure on the same.

52. In a spark plug, the combination of a relatively fixed member, anelectrode carrying insulator of relatively frangible material adapted toremovably seat therein and a single yielding pressure applying elementacting directly upon the insulator and rotatable to apply a yieldingpressure to lock it to its seat.

In testimony whereof I afix my signature in the presence of twoWitnesses.

HERMAN F. SADGEBURY. lVitnesses Cnes'rnn H. BnAsnL'roN, R. J. HAYNES.

